There is currently no effective process to efficiently construct 3-D vascular networks in biocompatible substrate materials at organ-level size scales. Although considerable progress has been made in the development of microfabrication technologies to address these needs, these techniques are often costly and much too slow to be practical for mass-production. Unless significant advances in scaffold fabrication speed and feature resolution can be achieved, it will be virtually impossible to culture and grow engineered tissues suitable for organ replacement. This exploratory research program will address these needs by developing advanced fabrication technologies capable of rapidly and inexpensively constructing 3-D vascular networks incorporating channel sizes ranging from 100 nm to 1 mm within tissue scaffold materials in a single step at whole-organ substrate size scales. This work will be the first time these fabrication processes have been harnessed for the construction of vascular microchannel networks, and will greatly enhance the ability to construct tissue engineered organ replacements. These goals will be accomplished through the following Specific Aims. Aim 1: Establish an entirely new electrostatic discharge-based technology to enable fabrication of 3-D fractal microchannel networks in plastic substrates for use as tissue engineering scaffolds. Aim 2: Perform cell culture experiments both on the surface of and within the 3-D vascularized scaffolds constructed in Aim 1 in order to establish the optimal range of parameters for use in tissue engineering applications. Upon completion of this exploratory research program, an entirely new family of fabrication tools will be available for construction of functional 3-D vascular networks in biocompatible scaffold materials. This advanced fabrication technology will impact the field of tissue engineering by, for the first time, making it feasible to mass produce scaffolds for whole-organ replacement in virtually any laboratory. To our knowledge, these electrostatic discharge-based fabrication techniques have never been applied toward construction of vascular structures for tissue engineering applications. These tools will enable the development of a new generation of engineered organ replacements, suitable for mass production and offering an unprecedented capability to mimic the structure and function of their natural counterparts. [unreadable] [unreadable] [unreadable]